Rolipram is a phosphodiesterase (PDE) type 4 inhibitor that has originally been developed by Schering AG, Berlin, Germany, as an antidepressant, before others and our laboratory documented the immunomodulatory properties of the drug. In the current trial, Rolipram will for the first time be tested as a novel immunomodulatory therapy in multiple sclerosis patients. The protocol involves a stage I for finding the highest individually well-tolerated drug dose, before stage II, and 8 months treatment period with this individually well-tolerated dose, will be conducted. The trial shall document the safety, tolerability an efficacy with respect to inhibition of central nervous inflammation in multiple sclerosis patients. Magnetic resonance imaging and clinical examinations will be used to study the above parameters, and immunological studies that will be conducted in parallel to the trial, will address the mechanism of action of Rolipram in MS.